1. Field of the Invention
This invention relates generally to an apparatus, having a platform that has two leveling orientations for handling semiconductor wafers in a manufacturing apparatus.
2. Description of the Related Art
Some semiconductor handling apparati include a vertically movable platform that holds and moves wafers before, during, and after a wafer treatment step. In one configuration, a wafer holding platform has two positions, a wafer loading position, and a second position in which cleaning, processing or other function may be performed. A wafer handling apparatus loads a wafer onto the platform when the platform is in the loading position. In order to properly load the wafer onto the platform, the wafer handling apparatus must be properly aligned with the platform when the platform is in the loading position. The platform is preferably aligned to receive the wafer in a plane that is parallel to the plane in which the handling apparatus is configured to deliver the wafer.
Once a wafer has been loaded onto the platform, the platform is moved to an upper position in which an upward facing sealing surface of the platform seals against a downward facing sealing surface of an upper chamber. The platform is moved upwards to allow the chamber to cap the platform, encapsulating the wafer in the upper chamber. In order to achieve an effective seal between the platform and the chamber, the sealing surface of the platform is preferably aligned to be parallel to the sealing surface of the chamber.
Depending upon the construction and design of the apparatus, the orientation of the wafer handling apparatus in one chamber may be slightly different from the orientation of the second chamber. Further, among several machines of the same model or design, there may be several different relative orientations between the wafer handling apparati and the other chambers. Accordingly, it would be advantageous to enable a platform to have a first adjustable orientation when the platform is in a first position and a second adjustable orientation when the platform is in a second position.
In the preferred embodiment, the present invention provides a dual orientation leveling platform for a semiconductor apparatus. The platform is preferably held atop a vertically moveable dual position leveling base by three draw screws, three push screws, and three spring-loaded pins. The leveling base is preferably configured to secure and orient the platform such that an upper surface of the platform is substantially horizontal with allowance for adjustments in each of two positions. When the base is in a wafer loading position, the platform is pushed to an upper position relative to the base by the spring-loaded pins. The orientation of the platform in the wafer loading position is preferably adjusted by the three draw screws, which pull the platform down against an upward force of the spring-loaded pins. The base also has an upper position in which the platform is forced into engagement with a lower mating surface of an upper chamber. The orientation of the platform in this sealing position is preferably adjusted by adjusting the height of the push screws, which limit the downward movement of the platform into the desired orientation with respect to the upper chamber. The draw screws can move downwardly with the platforms to enable the platform to move into a sealing position.